fairy godmother, a lot of it comes down to attitude. if you worry about the small stuff, you'll drive yourself crazy.
i flew by myself with my then 2 yr old and my 5 week old, and i was still recovering from a c-section.
9 hours? my trip was 36 hours door-to-door, this included a stint where we were diverted because of a snowstorm and sat on the runway IN the plane for over 4 hours!
ANY trip would be better than that!
and in all honesty, the kids were fantastic! they held up better than i did! but i didn't worry about the small stuff. i took a big tube of m&m's. it was my bribery tool. i would tell my 2 year old that if he was very good on the flight, that he would get some when we got off the plane (we flew: hong kong-tokyo-portland-vancouver-calgary-regina~where we circled for an hour then were diverted to ~saskatoon-regina) my son and his amazing memory would ask for the m&m's immediately when we got off the plane, even when the flight lasted for 10 hours!
the long flight that we were on had private tv's in the back of the seat in front of you, that kept him occupied for most of the flight. half of the new toys that i bought, we didn't use, we kept for the flight back.